Apparatus for casting metal ingots.



c. w. LUMMIS. APPARATUS FOR CASTING METAL INGOTS APPLICATION FILED SEPT. 16, 1914- l ,1%3 Q15@ Patented Julie 15, 1915.

Min asses.

referred to,

portion of UlllD $TATE CHARLES W. LUIVIMIS, 0F WORCESTER, MASSACHUSETTS.

APPARATUS FOR CASTING METAL INGOTS.

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Application filed September 1% all whom it may concern:

Be it known that I, CnAnLns "W. LUMMIs, a citizen of the United States, residing at Worcester, in the county of Worcester and Commonwealth of Massachusetts, have invented a new and useful Improvement in an Apparatus for Casting Metal ingots, of which the following, taken in connection with the accompanying drawings, is a'speciiication.

The present invention relates to improvements in apparatus for casting metal ingots in which metal, in a molten state, is poured from a container, such as a crucible or tilting furnace, into a mold or the like, to form an ingot. l

The apparatus of the present invention is especially applicable to the making of ingots of relatively small cross-sectional area, the

casting of which must be closely regulated to insure soundness, and freedom from dirt or slag. I

The pouring oi? the molten metal from the container into the mold, ordinarily effected by manual manipulation, must be conducted with the greatest of care, in order to obtain a homogeneous product, capable of being rolled, drawn, or extruded into sheets, rods, wires, or tubes. If the pouring proceeds too slowly, foreign matter, such as dirt, dross, or. slag, will be present in the finished ingot, since the solidification of themctal under a slow rate of pour occurs too close to the level of the molten metal as the pouring proceeds. {in the other hand, if the pouring proceeds too rapidly, the finished ingot is liable to be defective by reason of improper shrinkage. i It has been determined, from experiment, that in casting ingots of the character above the metal first entering the mold should be poured at a rate approximately equal to the rate at which the major the pouring operation is conducted, in the production of sound and homogeneous ingots. The ordingry mechanical devices for pouring fluids'from a til-ting container. do not produce this desired result. In such devices, the rate of tilting the cdntainer atthe beginning of the pour- 7 ing operation is practically the same as the rate imparted thereto during the balance of the pouring operation. This results in the fluid being poured initially at a very low rate, which gradually increases as thepour- Specification of Letters Patent.

Patented June 315, 11915. is, 1914. Serial No. 862,096.

ing head of the fluid over the lip of the container is gradually increased, until finally said pouring head becomes great enough to deliver the fluid as fast as it is displaced by the tilting of the container.

In order to establish the desired pouring rate practically coincident with the beginning of the pouring, it is necessary to first tilt the container at a rate greatly in excess of the normal tilting rate. This at once establishes a head of fluid over the lip of the contamer great enough to pour out the fluid at the desired rate; or in other words, secures a sudden delivery or initial slop of the fluid from the container. In the past, attempts have been made to obtain this action by supplementing the action of'the above described mechanical devices with hand controlled means for accelerating the initial tilting rate, but such methods have been found to be unsatisfactory by reason of the introduction of the human element, and have resulted in the production of defective and non-homogeneous castings due to the inability to pour the metal at the same rate or rates for successive pouring operations.

t is one of the objects of this invention to provide a mechanical means for delivering an initial slop of a molten metal or fluid from a tilting container which will be substantially the same for successive pouring operations.

A further object of this invention is to produce an improved apparatus for casting metal ingots, the apparatus being of such a character that the molten metal is poured into the mold at a substantially uniform rate, this rate being established substantially coincident with the beginning of the pouring operation and maintained during the formation of the major portion of the ingot.

he mechanism by which the above and other objects are attained, is illustrated in the accompanying drawings, in which- Figure 1 is a side elevation, partly in sec- .tion, of the mechanism, shown in connection with an ingot mold provided with an intermediate receiver, Fig. 2 is a top plan view of the same mechanism, shown in connection with an ingot mold which is not provided with such a strainer. Fig. 3 is a diagrammatic View illustrating the functions of the apparatus when a strainer is employed. Fig. 4 is a diagrammatic view illustrating the funcknown as a strainer v 'gulde characters refer to like the different figures. 2 of the drawings, 1 indicates a crucible for the molten metal, the

same being disposed within a suitable heating device or furnace 2. The furnace 2 and the crucible 1 constitute a container for the molten metal, which in the present embodiment of the invention is adapted to be tilted to ell'cctthe pouring of the metal. To this end the furnace is provided with trunnions 3, 3, which are pivoted in standards 4, 4:, to permit the swinging movement of the container about the axis of said. trunnions. The container is provided with a spout 5, which serves to deliver the metal which flows over the edge of the crucible 1 when the container is tilted, into a mold 6 disposed beneath said spout.

The mechanism by which the tilting of the container is effected may be widely varied. By way of example, one form of tilting mechanism is shown in Figs. 1 and 2, but it is to be understood. that my invention is not to be confined to the particular tilting mechanism shown and described, since any other mechanical means, capable of imparting to the tilting action of the container the characteristics hereinafter specified, is equally applicable to the carrying out of my invention. An arm 7 secured to the container has attached thereto a chain or cable 8, which is secured at its other end to the periphery of a rotatable winding drum 9, preferably provided with grooves 10 to the cable as it is wound. The drum may be rotated from a motor 11, the shaft of which carries a gear 12 in mesh with a gear 13 on a shaft 14. The shaft 14: is adapted to be connected to an alined shaft 15, when desired, by a suitable clutching device 16, of any well known type. The shaft 15 carries a gear 17 in mesh with a gear 18 on the shaft of the the gears 12', 13 and 17 18, being such as to rotate the drum at a suitable speed in winding up the cable 8 to elfcct the tilting of the container. Obviously, if the motor 11 be rotated at a constant speed, the engagement of the clutch 16 will cause the tilting of the container to proceed at a uniform rate, as illustrated by the full line 19, Fig. 5. In said Fig. 5 the equally spaced vertical lines 20 measure olf equal increments of time. Under such circumstances, as soon as the container has tilted far enough to bring the level of the metal over the e the metal will begin to dribble over said lip at a very slow rate, said rate increasing drum 9, the proportions of at which it is tilted strainer.

dge of the lip,

gradually as a head of metal is gradually established over said lip. The rate of flow of the metal is illustrated by the dotted line 21 in Fig. 5, and it will be seen that this rate does not reach the desired amplitude for the major portion of the pouring until well along in the pouring operation, the initial rate of flow of the metal being very low, so that solidification of the metal occurs too close to the level of the molten metal.

The present invention contemplates, as one way of securing the aforesaid initial slop of the metal from the container, the driving of the motor 11 at varying rates of speed, as determined by the desired rates of tilting to be imparted to the container.

In order to control the speed of the motor, for the purpose of effecting the desired rates of tilting, there is provided a suitable speed controller or resistance box 22, the operating arm 23 of which carries a gear 24 in mesh with a gear. 25 on the adjacent end of the shaft of the drum. The contact of said arm 23 with the several brush se' ents 26, 27, 28, 29 and 30 over which it is successively carried by its rotation produces, in the well known manner, a different speed of motor 11, for each segment. The speed changes of the motor are communicated of course to the drum 9 to vary the rate at which the cable is wound thereon.

In Fig. 1 the ingot mold 6 has fitted over its open upper end a strainer 31, comprising a cup shaped receptacle 'forming' a reservoir for the molten inetal above the mold, and having apertures 32 in its bottom through which the molten metal passes into the mold. In carrying out my invention in connection with a mold thus equipped, the operation of the apparatus is asfollowss- The maintenance of an adequate supply of molten metal in the strainer will insure passage of metal through the apertures 32 at a uniform rate throughout the major portion of the pouring operation, and this result involves merely a flow of metal into the strainer at a rate equal to the rate at which the metal flows through said apertures. But the establishment of such a supply or hea involves an initial rapid tilting tainer at a rate greatly in excess of the rate during the major per-'- tion of the pouring operation, in order to insure an initial slop over crucible to such an extent that an adequate supply or head is quickly produced in the After the motor 11 is speeded up, and the clutch 16 engaged, the drum 9 starts to wind up the cable 8, the speed of said drum being determined by the movement of the arm 23 onto the several controller segments 26, 27, 28, 29 and 30.

In Fig. 3, wherein the equally spaced vertical lines 33 measure oii' equal increments of time, the full line 3% denotes the rate of tiltof the con- 7' well as in those hor-izontal lines speeds of the motor. .=the points 0 and a,

' rate at which the ing the container, in response to the varying Said line 34, between indicates the tilting of the container to bring the molten metal on a level with the lip of the container, as determined by the movement of arm 23 over the segment 26; between the points a and b, the line indicates the rapidly increasing rate of tilting necessary to effect the above described initial slop of metal into the strainer, as determined by the rapid running of the motor while the arm 23 moves over the segment 27. In the same figure, the dotted line 35, from 6 to f, illustrates the metal is delivered or slopped into the strainer during the relatively short interval of time necessary to establish a head in the strainer under these circumstances. The two lines 34 and drop rapidly from the manimum points 6 and f to the points 0 and g respectively, when the controller arm 23 moves over the segments 28 and 29, to effect a reduction in the speed of the motor, and thereafter said lines between the points 0 and d, and g and it respectively, indicate a uniform rate of tilting the container and a uniform rate of flow of metal, said rates being the rates for the major portion of the pouring operation, as determined by the passage of the arm 23 over the long segment 30. i As previously stated, the uniform rate of flow indicated by the horizontal portion of line 35 between the points 0 and d is equal to the rate of flow through the apertures 32 of the strainer. It willbe understood that in this diagram, as shown in Figs. 4.- and 5, the indicating uniform tilting and uniform flow of metal are based on the assumption that the cpntainer is of such shape that equal quantities of the fluid are displaced, for equal increments of tilting. For containers of other shapes, the quantity of fluid displaced per unit of tilting must be determined for various degrees of tilting, and the tilting rate must be varied at different periods inthe operation to produce the uniform rate of pouring desired. After the mold has been filled the clutch l6 is disengaged and the crucib e is lowered in any well known manner in readiness to repeat the operation for another mold.

When no strainer is used in connection with the mold, ias shown in Fig. 2, the same initial slop of the metal over the lip of the crucible is necessary, and the rate of tilting required to produce said initial slop is indicated by the full line 36 on Fig. 4, which rises rapidly from the zero point to a maximum, thereafter falls rapidly and finally becomes uniform in character, in much the same manner as the line 34 on Fig 3. The initial XCGSS of this rate of tilting over the rate of tilting required during the major portion of the pouring operation need not be so great as when a strainer is employed, since there is no necessity for establishing the pouring head for such a strainer. The dotted line 27 in said Fig. at indicates the rate of flow of the metal from the container into the mold and shows the initial slop produced by the initial relatively high rate of tilting the container. The several points on the lines 36 and 37 corresponding to the points a, b, 0, d, e, f, g and h on the lines 34: and 35, Fig. 3, are indicated by the same reference letters with the addition of the prime mark. In the operation of the ap paratus under these conditions,'it is only necessary to properly vary the character and extent of the controller segments 26, 27, 28, 29 and 30 in order to secure the desired results.

In each of the examples shown, it is necessary to have the same quantity of fluid in the container at the beginning of each pouring operation, so that said fluid will be at the lip of the container at the same angle of tilt when the controller'arm 23 begins to move over the proper segment.

It is obvious that the underlying principles of my invention are the same, Whether a strainer be employed in connection with the mold or not. It is also obvious that the mechanical means employed for insuring the desired tilting of the container to produce the essential initial slop of the metal over the lip of the crucible, and the subsequent uniform pouring of the metal into the mold or into the strainer as the case may be, may take any convenient form, as for instance, a Winding drum rotatable at a uniform rate, but having a winding surface of variable radius, or any other mechanical means for controlling the tilting of the container in the manner described.

I claim,

1. Apparatus of the character described,

comprising a tilting container for fluids, and means for delivering an initial slop of fluid from said container.

2. Apparatus of the character described, comprising a tilting container for the pouring of fluids, and means for imparting a relatively rapid tilting motion to said con- I tainer at the beginning of the pouring operation.

3. Apparatus of the character described,

comprising a mold, a tilting container for the pouring of molten metal into said mold, and means for effecting an initial slop of molten metal from said container into said mold. I

4. Apparatus of the character described, comprising a mold, a tilting container for molten metal, a strainer adapted to receive molten metal from said container and to deliver the same to said mold, and means for causing an initial flow ofmetal from comprising an ingot mold, a container for molten metal. adapted to be tilted to pour:

its contents into said mold, and means for causing an initial tilting of said container at a rate greaterthan the rate of tilting required to pour the major portion of the ingot.

(3. Apparatus of the character described, comprising an. ingot mold, a tilting container for molten metal, a strainer ,adapted to receive molten metal from said container and to deliver the same to said mold, and means for causing an initial flow of metal into said strainer at a rate greater than the rate required to pour the major portion of the ingot.

7. r-\pparatus of the character described,

comprising a container for molten metal adapted to he tilted to effect a pouring of its contents, and means for causing an initial tilting of said container at a rate greater than the rate of tilting required for the major portion of the pouring operation, whereby an initial flow of metal from said container, at substantially the same rate as that required for the majorportion of th pouring operation, is produced.

8. Apparatus of the character described, comprising a container for mo ten metal adapted to be tilted of its contents, and means for establishing a head of molten metal over the edge of said container at the commencement of the pourto eflect the pouring.

ing operation, whereby an initial rate of flow substantially the same as the'rate required for the magorportion of the pouring operation is produced.

Dated this twelfth day of Septemher, 1914.

CHARLES W. LUMMIS.

Witnesses NELLIE l VHALEN, GEO. H. KENNEDY, J r. 

